Zhu Houcong was the grandson of Xianzong and the son of Zhu Youyuan, king of Xingxian. He was born in Anlu, Huguang (now Zhongxiang, Hubei). In 1521, Wuzong died without an heir. Yang Tinghe, the first assistant, welcomed him to the capital based on the article "Brothers end with brothers" in "Emperor Ming Ancestor Instructions". He ascended the throne in April at the age of fifteen. At the beginning of his ascension to the throne, Yang Tinghe presided over the elimination of righteousness and bad governance, and eliminated more than 100,000 redundant personnel such as Jinyiwei, which was praised by both the government and the public.
He insisted on respecting his biological father as the emperor, and held a three-year ceremonial discussion with Yang Tinghe and other court officials. In 1524, the court staff left the court and the court officials cried and remonstrated, thereby establishing absolute authority. In the early period of Jiajing period, he established sacrificial rituals and inspected the land of Xunqi Zhuang, which was quite effective. After the Renyin Palace Incident in 1542, he moved to Xiyuan and devoted himself to fasting, worshiping and practicing Xuan. He did not go to court for more than 20 years and relied on Yan Song, who was good at writing Qing Ci, to handle government affairs. Yan Song and his son had exclusive power for nearly 20 years.
During this period, Anda invaded the north frequently, and in 1550 their troops came to Beijing. The Japanese pirates were rampant in the southeast, and it took Qi Jiguang, Yu Dayou and others more than ten years to put them down. Yan Song resigned from office in 1562 and Xu Jie succeeded him as chief minister. In 1566, Hai Rui Shangshu, the head of the Ministry of Household Affairs, denounced him for being superstitious in alchemy and ignoring government affairs. In December of the forty-fifth year of Jiajing (January 1567), Shizong died of illness in Qianqing Palace. It is said that he was poisoned by taking elixirs for a long time.
Shizong was smart and decisive. When he came to the throne, he eradicated righteousness and bad governance, established the absolute authority of the imperial power with great ritual discussions, and improved the etiquette system, which was quite accomplished. However, he became addicted to Taoism in his middle age. He ignored the court for more than 20 years and focused on Yan Song. His administration was corrupt and his finances were in short supply. As a result, there were soldiers from the north approaching the city and Japanese pirates from the south wreaking havoc in the southeast. During his forty-five years in office, Ming Dynasty's trend of turning from governance to chaos has become increasingly obvious.